ECONNREFUSED when trying to get JSON from my server (MMM-json-feed)

Hi all,
I like to display a simple value that can be fetched from a JSON service. So I started with the MMM-json-feed module which is pretty much doing the trick with some test services that I found (e.g. http://ip.jsontest.com/).
It seemed to need just a simple adaptation of the config file, to load the JSON data from an URL in my private network.
Unfortunately this does not work, although my JSON service returns proper data (checked with my browser). The mm output is

MMM-json-feed sending request: GET http://raspberrypi.fritz.box/temp/
MMM-json-feed received
MMM-json-feed Error: connect ECONNREFUSED 192.168.178.33:80
Whoops! There was an uncaught exception...
TypeError: Cannot read property 'statusCode' of undefined
at Request._callback (/home/pi/MagicMirror/modules/MMM-json-feed/node_helper.js:15:48)
at self.callback (/home/pi/MagicMirror/node_modules/request/request.js:186:22)
at emitOne (events.js:96:13)
at Request.emit (events.js:191:7)
at Request.onRequestError (/home/pi/MagicMirror/node_modules/request/request.js:878:8)
at emitOne (events.js:96:13)
at ClientRequest.emit (events.js:191:7)
at Socket.socketErrorListener (_http_client.js:358:9)
at emitOne (events.js:96:13)
at Socket.emit (events.js:191:7)
MagicMirror will not quit, but it might be a good idea to check why this happened. Maybe no internet connection?
If you think this really is an issue, please open an issue on GitHub: https://github.com/MichMich/MagicMirror/issues

I thought it might relate to CORS and compared the headers of the JSONTest (http://ip.jsontest.com) and my JSON service. They both look quite similar. Nothing that make me believe there is something missing.
JSONTest:

@toh1000 Please post JSON response. I just spent a day trying to figure out why MM is so fickly regarding non-perfect JSON being sent over the socket. Loading JSON from a variable, just fine. Pushing the exact same JSON over a socket…had problems.

@E3V3A Also, @toh1000’s HTTP request included the header Accept-Encoding: gzip, deflate, so the test site responded with Content-Encoding: gzip. That’s totally appropriate, and usually this is handled transparently by the client, which will then provide the uncompressed response. However, the actual service (“My service”) responded with no compression.

ECONNREFUSED (Connection refused): No connection could be made because the target machine
actively refused it. This usually results from trying to connect to a service that is inactive on the
foreign host.

Solved:
The problem was that the module translated the server name into an up address and CherryPy was not configured to response to that.
Reconfiguring did the trick:this article explains how this is done
Thanks for your efforts.